1. Field of the Invention
The present invention generally relates to laboratory equipment and, more particularly, to an integral biological specimen collection tube and microscope slide constructed as a unitary device.
2. Description of the Related Art
Various types of laboratory devices have been devised in the past for the collection and handling of biological specimens. Certain ones of these devices are used particularly in laboratory centrifuges and the like. Complete urinalysis typically involves centrifugation of the specimen to isolate any sediment for microscopic study. Most procedures and devices currently in use require pouring the test liquid into a centrifuge tube and separately decanting the supernatant liquid from the sediment after centrifugation, then transferring the sediment to a microscope slide. Such procedures are time-consuming and expensive. Moreover, these individual steps are multiple in character, take the time of the technician, and increase the technician's contact with the specimen, thus increasing the risk of contracting disease from a specimen.
An improved combination collector tube and microscope slide member is described in U.S. Pat. No. 4,066,414. The tube and slide member are connected by a narrow, weak, frangible neck which is intended to be snapped through to remove the collection tube when the slide member is to be used. However, manufacturing and handling difficulties may occur with such a device. Moreover, the small delicate slide member must be separately handled after detachment, usually by mounting it in a secondary carrier, in order to place it into viewing position.
There remains a need for an improved type of device which can be used for initial biological liquid collection, subsequent centrifugation, sediment isolation and microscopic examination, all without transferring the test materials to other laboratory equipment. While the specimen tube of U.S. Pat. No. 3,814,522 would appear to present these features, it has been found that there are still serious drawbacks in that device. For example, the terminal chamber of the device, which is intended for microscope viewing, is aligned substantially with the central axis of the enlarged upper body portion (the centrifuge tube proper). This locates the slide portion substantially above the microscope stage, when in use, and undesirably affects the microscope optics. Moreover, it is impossible to view the slide portion of this device at different powers of microscope magnification without shifting the device out of the way while the microscope lens turret is rotated and then repositioning the device for viewing at the newly set level of magnification. This procedure is unduly time consuming and requires an added level of skill in the viewer to achieve proper results.
Another device for enabling a specimen to be viewed through a microscope after centrifuging is disclosed in U.S. Pat. No. 4,865,812. While this device is an improvement relative to the devices disclosed in the patents cited hereinabove, it still presents the limitation that its slide portion cannot be viewed at different powers of microscope magnification without shifting the device out of the way while the microscope lens turret is rotated.
My prior U.S. Pat. No. 5,030,421 discloses a device incorporating a longitudinally curved, concave section of the centrifuge tube portion of the device to provide microscope lens clearance. My present invention relates to other configurations for this purpose combined with additional beneficial features to achieve an improved integral centrifuge tube and specimen slide.